没人顶~~~自己搞定了,自己顶,给同样初学的参考下!
class oraDataConnection
    {
        string serveraddress = "carmng";
        string userid = "carmng";
        public OracleConnection getcon(string server,string user)
       //返回一个oracle连接
        {
            if (server == "")
                server = serveraddress;
            if (user == "")
                user = userid;
            string constr = "data source="+server+";user="+user+";password=cztesthp380";
            OracleConnection conora = new OracleConnection(constr);
            return conora;
        }
        public DataTable getdatatable(string server,string user,string cmdstr)
     //返回一个指定查询的表
        {
            string constr = "data source=" + server + ";user=" + user + ";password=cztesthp380";
            OracleConnection oracon = new OracleConnection(constr);
            oracon.Open();
            DataTable dt = new DataTable();
            OracleDataAdapter ada = new OracleDataAdapter(cmdstr, oracon);
            ada.Fill(dt);
            oracon.Close();
            return dt;
        }
        public DataTable getdatatable(OracleConnection oracon, string cmdstr)
     //返回一个指定查询的表
        {
            oracon.Open();
            DataTable dt = new DataTable();
            OracleDataAdapter ada = new OracleDataAdapter(cmdstr, oracon);
            ada.Fill(dt);
            oracon.Close();
            return dt;
        }
        public string insertitem(string server, string user, string cmdstr)
        //增加操作
        {
            if (cmdstr.Substring(0, 12) != "insert into ")
            {
                return "非insert语句";
            }
            string constr = "data source=" + server + ";user=" + user + ";password=cztesthp380";
            OracleConnection oracon = new OracleConnection(constr);
            oracon.Open();
            OracleCommand cmd = new OracleCommand(cmdstr, oracon);
            cmd.ExecuteNonQuery();
            oracon.Close();
            return "1";
        }
        public string updateitem(string server, string user, string cmdstr)
          //更新操作
        {
            if (cmdstr.Substring(0, 7) != "update ")
            {
                return "非update语句";
            }
            string constr = "data source=" + server + ";user=" + user + ";password=cztesthp380";
            OracleConnection oracon = new OracleConnection(constr);
            oracon.Open();
            OracleCommand cmd = new OracleCommand(cmdstr, oracon);
            cmd.ExecuteNonQuery();
            oracon.Close();
            return "1";
        }
        public string deleteitem(string server, string user, string cmdstr)
            //删除操作
        {
            if (cmdstr.Substring(0, 12) != "delete from ")
            {
                return "非delete语句";
            }
            string constr = "data source=" + server + ";user=" + user + ";password=cztesthp380";
            OracleConnection oracon = new OracleConnection(constr);
            oracon.Open();
            OracleCommand cmd = new OracleCommand(cmdstr, oracon);
            cmd.ExecuteNonQuery();
            oracon.Close();
            return "1";
        }
    }